This chart is from Seagrant. It shows the Great Lakes watershed in green and the five Great Lakes in blue. Also shown in this freshwater system are Lake Nipigon north of Lake Superior and Lake St. Clair between Lake Huron and Lake Erie. Although large, these lakes are not called Great Lakes. Starting from Lake Superior some say is shaped like a wolf's head, the water flows into Lake Michigan and Lake Huron, then into Lake St. Clair and Lake Erie. The freshwater then takes a tremendous plunge over Niagara Falls into Lake Ontario and from there it flows out the St. Lawrence River until it reaches the Atlantic Ocean. Also seen on this chart are the states in the United States and the provinces in Canada surrounding the Great Lakes. Canada and the U.S. share this mighty freshwater system.
Read more about the Great Lakes in my critically acclaimed book, The Dynamic Great Lakes Now available from the Amazon.com Kindle for $9.95, Barnes & Noble in paperback and many other fine bookstores.